Improve home ventilation to reduce radon levels, WHO warns

30 January 2006 | Geneva -Homeowners and building managers in the northern hemisphere should take measures, more than ever at this time of year, to improve indoor ventilation in order to reduce radon levels in homes, the World Health Organization (WHO) warned today.

The highest levels of radioactive radon gas in homes and other buildings occur during the winter months. This is because windows are normally kept closed, or even sealed, during winter to keep in warm air and save energy costs. This traps radon gas, which seeps in through small cracks in the foundations of buildings. Inhabitants and users of these buildings are then exposed to radon that can damage their lungs over time. After smoking, radon is the second most important risk factor for lung cancer worldwide, causing tens of thousands of lung cancer deaths every year.

"Radon is an underestimated but widespread danger to health. Many people are unknowingly exposed to radon every day in the buildings where they live and work. We have to make people aware of the existence of radon as a danger, and the means of mitigating this public health threat," said Dr Mike Repacholi, head of the Radiation and Health programme at WHO headquarters in Geneva.

Measuring radon levels in homes and public buildings is an important first step, and environmental health offices can advise on this. If elevated radon levels are found, individuals can take simple actions to protect their health, for example by ensuring adequate ventilation through installation of ventilation systems. To limit entry of radon gas into buildings, cracks in floor surfaces in contact with the ground should be sealed. New buildings should be constructed with sealed foundations that keep radon levels low.

Radon is a natural radioactive gas and a major contributor to people's environmental radiation exposure. The gas emanates from soil into the air, its concentration mainly depending on the uranium content of the soil.

WHO's call for greater attention to be given to reducing radon exposure comes as its collaborating centre for radon, the United States Environmental Protection Agency, conducts its National Radon Action Month.

With the launch of the International Radon Project in 2005, WHO has initiated work with the governments of more than 30 countries to reduce the health risks associated with radon. WHO and its partners are identifying and promoting programmes that reduce the health impact of elevated levels of indoor radon gas. This work includes the development of guidelines for national authorities to manage radon risks through effective communication and mitigation programmes.